The inventive concept relates to a chemical-mechanical polishing (CMP) apparatus for manufacturing a semiconductor device.
In a general face-up type CMP apparatus, a spin chuck supports a non-polished surface of a wafer by vacuum adsorbing the non-polished surface so as for a polished surface of the wafer to face upward, and a polisher moves along the wafer surface to polish the wafer surface. The CMP apparatus may actively correspond to the wafer surface since a rotational axis of the polisher may be inclined, that is, may be naturally or intentionally tilted, within an allowable range.
Such a polisher polishes the wafer surface by moving along the wafer surface. While the polisher polishes the center part of the wafer surface, a uniform wafer pressure is exerted to the entire polisher from the wafer and thus the polisher may be maintained in a horizontal state. However, when a part of the polisher is out of an edge part of the wafer surface in order to polish the edge part of the wafer surface, the rotational axis of the polisher is tilted in an edge part direction due to an unbalanced pressure and thereby the polisher may not maintain its horizontal state and is tilted. Thus, a polishing pad of the tilted polisher and the wafer that rotates in a horizontal state collide with each other and thereby the edge part of the wafer contacted due to the collision is severely damaged. Consequently, polishing uniformity of the center part and edge part of the wafer surface is deteriorated.